Plating metals.



UNITED STATES PATE;

WILLIAM E. WATKINS, or new YORK, n. r.

rLA'rInG METALS.

No Drawing.

To all whom it may concern:

Be it known that I, WILLIAM E. WAT- KINs, a citizen of the United States, residing inthe city, county, and State of New York, have invented certain new and useful Improvements in Plating Metals; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In an application for Letters Patent of the United States filed by me on the twentyfirst day of August, 1913, Ser. No. 785,947, I have described the plating of one metal with another by applying to the metal to be plated a reducible compound of the plating metal which compound is held in suspension in a suitable viscous reducing agent, the resulting mixture constituting a paste or suspension adapted to be spread inan even dense layer upon the metal to be plated, as for instance, upon the upper-and lower surfaces of a sheet of iron or steel. The iron or steel sheet thus coated is then subjected to furnace heat, of such degree and duration that its surfaces will lee-covered with a non-stripping layer of the plating metaL' It has been found that, in practice, there is a limitation upon the amount of the plat ing metal that can readily be applied in one furnace operation in following this procedure. This limitation is in part due to the required viscosity of the applied coating of the reducible metal compound and its liquid carrier, and, in part, to the fact that a certain proportion of the metal compound escapes reduction because of the insufficient reducing power of the reducing vehicle. As a consequence, not only is the quantity of the plating metal correspondingly diminished, but a portion of the 're ducible compound escapes reduction and must be removed from the plating surface upon which it tends to collect.

The present invention is designed to remedy the defects noted and to propor tionately enhance the efliciency and availabilityof the general operation. It de-' destructive in vmolten weight of Specification of Letters Patent. Patented Sept, 12', 1916, Application filed August 17, 1915. Serial No. 45,854.

the resultant mixture will have the requisite viscosity and will likewise have its reducing power sufficiently increased so that the metal of the reducible compound may be deposited in its substantial entirety as plating metal upon the metal to be plated.

' In the practice of the invention, the finely-divided solid reducing agent niay conveniently be finely divided carbon any of its forms, as, for instance, finely ground coal, coke, or charcoal, or carbon obtained in the form of lamp black or the likeby the distillation of a hydrocarbon. For example, if the metal to be coated is a sheet of iron or steel (such as the iron sheets employed in the familiar operation of making tinned plate by dipping thesheet tin) and where the reducible compound of the plating metal is copper oxid, I have found that a suitable paste or suspension appropriate to the complete re"- duction of the copper oxid, under the furnaceconditions specified in my application referred to, by weight Mexican crude oil (having a specific gravity represented byv 7% pounds to the gallon and 1 K to part by weight of finely divided -carbon, as, for instance, lamp black;

- In practice, it will be expedient and desirable to grind the copper oxid, the Mexican crude oil, and the finely divided carbon together, so that the resulting paste or sus-- pension will be of a character wherein the solid particles of the copper oxid and of the finely divided carbon Will be distributed with substantial uniformity'throughout the mass, which latter will have a viscosity sufiicient to permit it to be applied by coating rolls in a dense adhesive uniform layer upon both sides of the iron or steel sheet. When the sheet, thus coated, is subjected to a temperature of 2000 F. or thereabout, as contemplated in my application hereinbefore referred to, andv for a su cient period (if time, as therein specified, itwill be found that the dapper oxid has been reduced in its substantial entirety and that it has formed a may bemade by adding one part a of the copper oxid, one part by' plating of correspondingly increased thickness upon the iron or steel sheet.

In some instances, there may be added further to the suspension or paste one part steps: applying to the by weight of finely divided metallic copper, as, for instance, finely divided metallic copper precipitated as such from a copper solution, or obtained by the reduction of a finely divided copper compound. I have discovered that the paste will tolerate this additional quantity of finely divided solid material without lowering its viscosity below the limit required for coating the iron or steel sheets with the paste, and also that the presence of the reducing spreading ve hicle and the finely divided carbon is sufiicient to protect until it is melted; whereupon, together with the copper reduced from the copper oxid, it forms a plating upon the iron or steel sheet of a correspondingly increased thickness.

It will also be understood that, instead of using Mexican crude oil or other oil having an asphaltic base, I may employ any other suitable spreading liquid as, for instance, a lighter hydro-carbon such as kerosene, or I may even employ water as the spreading vehicle, but, in these instances, it will be necessary to increase the amount of finely divided carbon employed, so that the reducing effect upon the copper .oxid may sufiice to obtain the complete reduction to the metallic state.

If the furnace conditions are such that the copper plating obtained as the result of the process should be found to have a superficial layer of iron oxid, this may readily be removed by abrasion, pickling, or in any other suitable manner.

What I claim is:

1. The process of plating one metal with another, which comprises the following metal to be plated a coating comprising a reducible compound. of the plating metal, asuitable liquid vehicle therefor, and a finely "divided solid reducing agent; and subjecting the metal to be plated, together with the coating thereon, to heat, the quantity of said coating and the intensity and duration of the heatbeing suflicient to form a plating layer of the plating metal adherent to the metal to be plated.

2. The process of plating one metal with comprises the following another, which the metal to be plated a steps: applying to coating comprising a reducible compound a suitable reducing and a finely divided and sub ecting the of the plating metal, liquid vehicle therefor, solid reducing agent;

metal to be plated, together with'the coating thereon, to heat, the quantity of said coating and the intensity and durat1on of the heat being sufiicient to form a plating layer of the plating metal adherent to the metal to be plated.

the finely divided copper,

.of copper,

3. The process of plating one metal with another, which comprises the following steps: applying to the metal to be plated a coating comprising a reducible compound of the plating metal, a suitable reducing liquid vehicle therefor, and finely divided particles of the plating metal; and subjecting the metal to be plated, together with the coating thereon, to heat, the quantity of said coating and the intensity and duration of the heat being sufficient to form a plating layer of the plating metal adherent to the metal to be plated.

4:. Theprocess of plating one metal with another, which comprises the following steps: applying to the metal to be plated a coating comprising a reducible compound of the plating metal, a suitable liquid vehicle therefor, a finely divided solid reducing agent and finely divided particles of the plating metal; and subjecting the metal to be plated, together with the coating thereon, to

heat, the quantity of said coating and the in-' tensity and duration of the heat being sufficient to form a plating layer of the plating metal adherent to the metal to be plated.

5. The process of plating iron-or steel with copper, which comprises the following steps: applying tothe metal to be plated, a coating comprising a reducible compoun a suitable liquid vehicle therefor, and a finely divided solid reducing agent; and subjecting the metal to be plated, together with the coating thereon, to heat, the quantity of said coating, and the intensity and duration of the .heat being suflicient to form a plating layer of copper adherent to the metal to be plated.

6. The process of plating iron or steel with a suitable reducing liquid vehicle therefor, and a finely divided solid reducing agent;

and subjecting the metal to be plated, together with the coating thereon, to heat, the quantity of said coating and the intensity and duration of form a plating layer of copper adherent to the metal to be plated.

7. The process of plating iron or steel with copper, which comprises the following steps: applying to the metal to be plated, a coating comprising a reducible compound of copper, a suitable liquid vehicle therefor, a finely divided solid reducing agent and finely divided particles of copper; and subjecting the metal to be plated,-together with the coating thereon, to heat, the quantity of said coating and the intensity and duration of the heat being sufiicient to form a plating layer of copper adherent-to the metal to be heated. I

8. The process of plating iron of steel the heat being sufiicient to with copper, which comprises the following with the coating thereon, to heat, the quansteps: applying to the metal to be plated, a tity of said coating and the intensity and coating comprising a reducible compound of duration of the heat being suflicient to form 10 copper, a suitable reducing liquid vehicle a plating layer'of copper adherent to the therefor, finely divided particles of carbon, metal to be plated.

and finely divided particles of copper; and Q In testimony whereof I aflix my signature. subjecting the metal to be plated, together WILLIAM E. WATKINS. 

